Smoke, they conceiving it might be useful to the Citizens of Paris. I promis'd to do it, but had not time while I staid there. When at Sea, I wrote that with some other Pieces, which being read to our Philosophical Society here, are now printed in their Transactions. I send you herewith a Copy. I address'd it to you, wishing that if those publick Spirited Gentlemen continue in the mind of publishing it, you would do me the Honour to take care of the Translation. Cadet has my Plate for it ready engrav'd, which I left with him. The other two Pieces are, One on the Causes and Cure of Smoky Chimneys address'd to D' Ingenhousz our common Friend, the other containing maritime Observations address'd to our common Brother. M' Grand will show them to you if you desire it: tho' you will receive the Volume (by the first Ship from this Port,) which contains them all.

a Volume also for the Academy.

I am, ever, my dear Friend,

Yours most affectionately

M.

There is

Having at length been persuaded to build two Houses, this Year, I wrote to you sometime since requesting you to put your self in Cash for me by selling my Actions of the Caisse

d'Escompte; and I have since drawn on you two Bills for Two hundred and Fifty Pound's Sterling each, dated the 29th and the 30th of July last, or 28th and 29th, both Setts in favour of the same Person M' Meade Merchant of this City, and payable in London at 40 Days sight, which I make no doubt will be duly honoured. I must continue to draw from time to time as my Buildings go on, and I request you would keep me advis'd of the Payment that I may continually see how our Account goes on. I bespoke before I left France some Printing Letters of Mr Didot, they are for Benjamin. If ready I request you would pay for them, and ship them for me by the first convenient Opportunity. I do not know the Amount. I wish you to buy for me also the Marquis de Chastellux's Voyages in America. I am much in Arrear with my Friends in France on the Score of Correspondence. But by the first Ship going from hence thither, I will endeavour to clear my Accounts. This goes via New York. My Family continues in good Health, Thanks to God: Those you knew of us join in best Wishes of Prosperity to you & yours; and I am ever, my dear Friend,

Yours most affectionately

B. FRANKLIN.

1656. TO JOHN JAY

(L. C.)

Philad", Aug 24, 1786.

DEAR SIR:- I hear a Treaty is compleated with Portugal. As soon as it may be made public, you will oblige me much by favouring me with a Copy of it.

The Monument of General Montgomery, may I ask what

is become of it? It has formerly been said, that Republicks are naturally ungrateful. The immediate Resolution of Congress for erecting that Monument contradicts that Opinion; but the letting the Monument lie eight Years unpack'd, if true, seems rather a Confirmation of it.

On a Review of my Affairs since my Return, I think it proper to make some Change in the Dispositions of my Will. Having no other Copy on this Side the Water but that in your Possession, I wish you to send it to me, which will much oblige, dear Sir, your most obed' Servant,

B. FRANKLIN.

1657. ON THERMOMETERS

September 13, 1786.

THE two thermometers most generally in use at present, among the philosophers of Europe, are those of Réaumur and Fahrenheit. The French use Réaumur's, the English Fahrenheit's.

In their respective graduations, Réaumur marked his freezing point o, Fahrenheit fixed his at 32 of his degrees above o, and two of his degrees are just equal to one of Réaumur's. I know that in some instruments this equality is not exact; but, in two which I have, the one Réaumur's, made by Cappy in Paris, the other Fahrenheit's, by Nairne, London, it is precisely so, they hanging together in the same room. And those workmen are famed for their exactness.

In reading, one frequently finds degrees of heat and cold. mentioned, as measured by one or the other of those thermometers, and one is at a loss to reduce that least known to the other.

Rule.

Suppose the degree mentioned is 25 of Réaumur, which is 25 degrees above o, or its freezing point, and you would know to what degree of Fahrenheit that answers;

Double the 25, which will give you 50 of Fahrenheit's, and to them add 32, his number at the freezing point, and you will have 82, the degree of Fahrenheit's equal to 25 of Réaumur.

On the contrary, if you would reduce Fahrenheit to Réaumur, first subtract 32, and then take half of the remainder; thus taking 32 from 82, there remains 50, and the half of 50

is 25.

This answers in all cases where the degree is above the freezing point.

If below, double the degrees of Réaumur, and subtract them from the 32 of Fahrenheit, which will give you the equivalent degree of his scale. Thus, suppose it 5 below 0, or the freezing point of Réaumur; twice 5 is 10, which deducted from 32, Fahrenheit's freezing point, gives you 22 as the equivalent degree of his thermometer.

And halving the degrees of Fahrenheit that are less than 32, you have the degree of Réaumur. Thus 22 of Fahrenheit being 10 degrees less than 32, the half of 10 is 5, the equivalent degree of Réaumur. B. FRANKLIN.

1658. TO MRS. JANE MECOM

(L. C.)

Philada Sept. 21, 1786.

MY DEAR SISTER: - I received your kind Letter of the 25th past, by our Cousin Williams, who, besides, informs me of your Welfare, which gives me great Pleasure.

Your Grandson having finished all the Business I had to employ him in, set out for Boston a few Days before Cousin Williams arrived. I suppose he may be with you before this time.

I had begun to build two good Houses next the Street, instead of three old Ones which I pull'd down, but my Neighbour disputing my Bounds, I have been obliged to postpone till that Dispute is settled by Law. In the meantime, the Workmen, and Materials being ready, I have ordered an Addition to the House I live in, it being too small for our growing Family. There are a good many Hands employ'd, and I hope to see it cover'd in before Winter. I propose to have in it a long Room for my Library and Instruments, with two good Bedchambers and two Garrets. The Library is to be even with the Floor of my best old Chamber; and the Story under it will for the present be employ'd only to hold Wood, but may be made into Rooms hereafter. This Addition is on the Side next the River. I hardly know how to justify building a library at an Age that will so soon oblige me to quit it; but we are apt to forget that we are grown old, and Building is an Amusement.

I think you will do well to instruct your Grandson in the Art of making that Soap. It may be of use to him, and 'tis pity it should be lost.

Some knowing Ones here in Matters of Weather predict a hard Winter. Permit me to have the Pleasure of helping to keep you warm. Lay in a good Stock of Firewood, and draw upon me for the Amount. Your Bill shall be paid upon Sight by your affectionate Brother,

B. FRANKLIN.